The Boston Red Sox and David Ortiz remain far apart in talks about his 2012 contract, making a salary arbitration hearing increasingly likely, one major-league source told FOXSports.com.

The sides have made little recent progress in negotiations, the source indicated, setting up what could be an uncomfortable hearing for the 36-year-old.

Ortiz has been one of the most popular and productive Red Sox since joining the organization before the 2003 season. In a hearing – which has been tentatively scheduled for mid-February – he would listen to Red Sox representatives argue why he deserves a $12.65 million salary, rather than the $16.5 million he has requested.

For now, the sides are allowed to settle at a number between those figures. But once a hearing begins, the arbitrator is obligated to choose one number or the other. The stakes are very high for the Red Sox; if they lose a hearing, they will have $4 million less to spend on upgrading their pitching staff.

Ortiz was the most productive fulltime designated hitter in the American League last year. He amassed a .953 OPS, making it his best season since 2007, when he finished fourth in the American League MVP voting.